1. Field of the Invention
The present invention is directed to a method for manufacturing a glow cathode for an electron tube, the glow cathode comprising a layer of an alloy of a metal of the group Ru, Rh, Pd, Os, Ir, Pt, Re and an element of the group Ba, Ca, La, Y, Gd, Ce, Th, U on a substrate.
2. Description of the Prior Art
A glow cathode is used as an electron emitter in devices such as x-ray tubes. A layer of the composition cited above is located at least in the region in which the electron emission should preferably ensue. Such layers have a high electron emission capability at low operating temperatures, and thus have a long useful life with improved mechanical stability.
European Application 0 143 222 discloses a method for manufacturing a glow cathode of the type initially cited. In this known method, the alloy or a corresponding intermetallic compound is first produced by a smelting or powder metallurgical procedure and is then pulverized and applied onto the substrate in a wet-mechanical, chemical, galvanic or smelting metallurgical procedure. The manufacture of coatings according to this known method thus involves substantial outlay and is correspondingly costly.